The Research Of QoS-based Ad Hoc Multi-path Routing Protocol

The Ad Hoc network is a special of wireless mobile communications network,it has a dynamic topology,network nodes can arbitrary move,which can dynamically join or leave the network. Ad Hoc network has not any central and fixed infrastructures, network nodes are equal and each node has the dual function of host and router,it forms a multi-hop distributed network which regarding intermediate host nodes as the relay. The traditional internet routing protocol can not meet the demand of Ad Hoc network because the topology of which frequently changes,so the routing protocol is always an important research field of Ad Hoc network.This article briefly introduces the basic concept,characteristics,application fields,as well as network structure and key technology.Then this thesis emphatically introduces the Ad Hoc network routing technology,analyzes problems facing and designs requirements of the Ad Hoc network routing protocol,and then introduces the working principle of a typical routing protocols according to routing protocol classification. Then this thesis introduces the NS2 simulation platform, expoundes the working principle and the mobile node model of NS2,and introduces the process of designing simulation program,also the classical Ad Hoc network routing protocol DSDV,AODV and DSR are simulated.Based on analyzing the problems of the single-path routing,this thesis proposes a QoS-based Ad Hoc multi-path protocol QM-AODV. It uses the DSR protocol agreement "path record" to find the multi-path routing,meanwhile,in order to ensure reliability and stability in the process of multi-path routing transmission,it introducts the minimum available bandwidth to support QoS, so it can find three path of uncorrelated node in the process of route discovery and satisfy certain QoS service. Then this thesis compares protocol QM-AODV and AODV through simulation software NS2,the result shows that QM-AODV protocol reduces route cost,increases packet delivery ratio, reduces delay, improves network service quality.